4 foot Generator HVAC pad

[workinallthetime]

We are building a new home in a flood plane, before you say 登h gosh I have lived on or maintained this property for 40 years and I have seen the worst flooding to hit the area. With this in mind we are building a coastal style home where the ground floor is the garage and has high concrete walls way above the flood zone. However I must raise the gen and hvac pad to keep them out of a possible flood. I do not want the pad physically attached to the house because of vibrations when it does need to run. I am thinking a dirt pad with timber walls possibly out of 6x6 pt lumber.
Any thoughts?

 

[RedNeckRacin]

Yeah, no! Wood floats remember. (Assuming you are setting the wood on grade) you need to build every thing as if it's going to reach the 100yr flood elevation. If I needed to rely on a generator (why else would you install it?) I'd be taking every precaution to make sure it was safe and secure when I needed it. If I missed something please correct me.

 

[workinallthetime]

Agree wood wood floats and wood in contact with earth will eventually rot out. My contractor suggested just a earth pad, that’s a lot of earth and I can’t imagine it will look that good. I would need to create a 4 foot pad for the units and slope it to shed water and mow the area. This is why I am toying with some sort of enclosure, perhaps concrete walls?

 

[Einthewoods]

Clearly this is much lower to the ground than you are probably thinking, but the idea seems to be on the path of what you could do. Elevate it higher with bracing for the legs and solid posts in the ground.

Generator Elevated platform

 

[workinallthetime]

I like it, might use piers with the post on top to eliminate ground contact. I have several large power poles and bridge beams that may serve as supports once cut to size.

 

[rustyshakelford]

I would set posts and built it on a platform. Then place wood fence panels around it for looks and to help a little with noise. Make it large enough you can walk all the way around it inside

Brett

 

[RedNeckRacin]

How tall of a dirt pad? I was picturing water being 6 foot deep and the pad being 6 inches high. I like the elevated platform with a walkway around it.

 

[workinallthetime]

Pad at 4 feet will be 3 feet above the 100 flood elevation, elevation of the 1st living space will be 9 to 10 feet above the elevation. Power goes down on a regular basis in the area thus the need for the gen.
Gen set / hvac deck I’m thinking is the way to go.

 

[RedNeckRacin]

Don't forget, it didn't happen if there are no pictures. ..

 

[fried1765]

Pad at 4 feet will be 3 feet above the 100 flood elevation, elevation of the 1st living space will be 9 to 10 feet above the elevation. Power goes down on a regular basis in the area thus the need for the gen.
Gen set / hvac deck I’m thinking is the way to go.

Sonotubes (with rebar cages), and build PT deck on top.

 

[newbury]

Several things -
First - When was this "100 yr flood" elevation last updated and by whom/what agency?
With the continuing development of areas in watersheds I've read of many areas having "100 year floods" frequently. As more areas get paved and have roofs put over them what rain/snow falls has to go somewhere. What is the 500 year mark? Note that Houston has had three "500 yr flood" events in the last 3 years A ‘5-Year Flood’ Could Happen Again Sooner Than You Think. Here’s Why. - The New York Times
Hurricane Harvey is third '5-year' flood in Houston in 3 years - The Washington Post


Second - How big is your equipment? Could you dedicate a small raft/john boat to it? If your flooding is away from high current areas a tightly tethered floating platform could handle a wide range of heights.

 

[Deere Dude]

I would put footings and build it up with cement block to the correct height, then cement a 4x5' pad or whatever is the correct size on top of it. Maybe stucco the block so it looks nicer.

 

[Stimw]

Utility poles below frost line with platform on top close to your first floor height.
As stated, close in the bottom, then you have a storage shed for regular time.

 

[EddieWalker]

I do not want the pad physically attached to the house because of vibrations when it does need to run.

I'm really at a loss as to why you feel vibrations are a good reason to build a separate pad for the HVAC and a generator. In my opinion, you are creating a can of worms doing this that will always be a source of problems. During the course of building the foundation and first floor concrete walls, it will be simple and very cost effective to do this at the same time.

Without seeing your plans, I would look into an attached storage shed with your HVAC and Generator on the second level, or at least above the worse possible height of the water when it floods.

The last thing I would want to do is have something like a generator or your HVAC condenser sitting on a dirt pad with a wood frame during a major flood. To me, that's just asking for problems.

If you absolutely have to have it separate from the house on a separate pad, go concrete and block. If that's too ugly for you, dress it up after it's done. Paint, add wood, or rock to it.

 

[workinallthetime]

I'm really at a loss as to why you feel vibrations are a good reason to build a separate pad for the HVAC and a generator. In my opinion, you are creating a can of worms doing this that will always be a source of problems. During the course of building the foundation and first floor concrete walls, it will be simple and very cost effective to do this at the same time.

Without seeing your plans, I would look into an attached storage shed with your HVAC and Generator on the second level, or at least above the worse possible height of the water when it floods.

The last thing I would want to do is have something like a generator or your HVAC condenser sitting on a dirt pad with a wood frame during a major flood. To me, that's just asking for problems.

If you absolutely have to have it separate from the house on a separate pad, go concrete and block. If that's too ugly for you, dress it up after it's done. Paint, add wood, or rock to it.

Eddie,
Man i think you have been on here since i had a BX23, that was a long time ago!
My builder has had some experience in the area with gen sets and stated the vibrations will drive us crazy as it did with his last build, they went back several times to address the issue and ended up isolating the gen pad from the house. My original design had the gen / HVAC systems on an extension of the rear deck but he has strongly recommended against it.
I would agree a concrete structure would be ideal on top of all the suggestions and I can think of a lot of uses under the units.

 

[Deere Dude]

At work I installed a 3 HP electric pressure washer and mounted it to some steel beams in the factory setting. The floor above was an office. A day later we had to isolate the washer because of vibration traveling because it was an aggravating nuisance. That generator would be much worse than a washer. Isolate it and get it above the flood level IMO

 

[workinallthetime]

ended up with piers and 6 x 6 posts, 2 x 12 subframe, 2 x 6 decking. After a year in the bang from the xfer switch still makes me jump but the generator and a/c units do not vibrate the house at all.
The mechanical deck or "mech deck" is isolated from the house completely.

 

[EddieWalker]

Thanks for the update. Any pictures?

 

[fitter1]

What is your fuel supply for the generator? Tanks will float away, even buried tanks that are half full. A buried natural gas line would be ok.